Refrigeration method and apparatus



June 28, 1932'. E: LL 1,864,661

REFRIGERATION METHOD AND APPARATUS Filed Feb. 2a, 1926 'r Sheets-Sheet 1June 28, 1932. E. B. MILLER REFRIGERATION METHOD AND APPARATUS FiledFeb. 26, 1926 7 Sheets-Sheet 2 SN .000% n 5 21 G E-wi 5 June 28, 1932.E. B. MILLER 4,

REFRIGERATION METHOD AND APPARATUS Filed Feb. as, 1926 Sheets-SheetJuile- 28, 1932. I E. B. MILLER REFRIGERATION METHOD AND APPARATUS FiledFb'. 26, 1926 7 Sheets-Sheet 4 mw a attain;

June 23, 1932. E. B. MILLER REFRIGERATION METHOD AND AP PARATUS Fil edFeb. 26, 1926 7 Sheets-Sheet 5 vweutoz June 28, 1932.

E. MILLER REFRIGERATION METHOD AND APPAR ATUS Filed Feb. 26, 1926 7Sheets-Sheet .6

June 28, 1932. E. B. MlLLEF REFRIGERATION METHdD AND APPARATUS FiledFeb. 26, 1926 7 Sheets-Sheet 7 l vide an apparatus that requires noattend- Patented June 28, 1932 I UNITED STATES PATENT orrl'ca ERNESTmnnwrn MiLLER, or summons, MARYLAND, ASSIGNOR 'ro SILICA ear. eon--ronerron, or BALTIMORE, MARYLAND, A conromrron or MARYLAND REFRIGERATIONMETHOD AND APPARATUS Application filed February 26, 1926. Serial No.90,827.

The present invention relates to a method and apparatus forrefrigeration, and more particularly to the type of refrigerationwherein a liquid is evaporated and the vapor adsorbed in asolid, porousadsorbent.

' The main object of the invention is to provide an improved, fullyautomatic apparatus ofv this type wherein there is no compressor, pumpor similar machinery.

Another object of the invention is to proance, and is thoroughlydependable and foolproof so that it is suitable for the most eX- actingrequirements, for example, refrigerating railroad cars. l p 7 Theprincipal features of novelty are as follows: a p

1. An automatic control of the valve in the conduit connecting theevaporator and adsorber, so that the valve open when the porous materialis adsorblng vapor, and is closed when the material is being activatedand cooled.

2. Automatic means to keep the ice-making evaporator at a lowertemperature than the evaporator used for cooling the refrigeratingchamber. 4

3. The means and method "of ridding the the adsorbing material rapidly.This is obtained by condensing part of the vapor, liberated duringactivation, at sub-atmospheric pressure and the balance at a gherpressure. 5; Bidding the system of permanent gases byventing them fromthe second stage of the condenser, to the'atmosphere. y 6. Venting thepermanent gases from the condensed vapors when the latter are hot.

Because the condensedvapor is hot, there is a minimum of air entrainedtherewith.

7. Controlling the return ,of the condensed vapor to the evaporator sothat it varies inversely with the refrigerating effect being obtained;that is, the higher the temperature of the liquid in the evaporator ofthe refrigerating chamber, the more rapid the return of the condensedvapors to the evaporator.

8. Automatically controlling the activation of the adsorbing material.This activation may be governed by the refrigerating effect as indicatedby'the temperature of the liquid in the evaporator; also by the amountof vapor condensed in the condenser and by g the temperature of thevapor liberated from the adsorbing material. The activation, after it isinitiated, continues until the temperature of the liberated vapor falls,or in other words, until practically all .of the vapor is liberated fromthe adsorbing material.

9. Means connecting the two stages of the I .condenser so that vapor andcondensate from the first stage are not discharged into the sec- 0ndstage until the pressure in the first sta slightly exceeds that in thesecond.

10. Means connecting the adsorber and the condenser, which cuts oficommunication between these two parts when the adsorber is adsorbingvapor but permits discharge of vapor to the condenser when the adsorbingmaterial is being activated.

adsorbers, means for activating said adsorbersm rotation, the lntervalsbetween successive activations depending upon the refrig erating effect;that is to say, the warmer the liquid in the evaporator, the morefrequent the activations.

Other features ofnovelty will be apparent from the description 'taken inconnection with the drawings, in which: i

Figure 1 is a diagrammatic illustration 0 11. In an apparatus having aplurality of an apparatus embodying "the present invention, and moreparticularly designed for the smaller sizes such ashousehold apparatus;

Figure 2 is a'diagrammatic illustration of an apparatus designed forlarger units; a Figure 3 is a sectional elevation taken substantially onthe line 33 of Figure 2;

Figure 4 is a somewhat diagrammatic illustrationof the gas distributorand the means.

for actuating the same from thevapor valves Figure 5 is a plan view-ofthe mechanism shown in Figure .4;

. Figure 6 is an elevation, mostly in section,

the device controlling V distributor taken substantially on the line 6-6of Figure V Figure 10 is a sectional elevation taken substantially onthe line 1010 of Figure 9;

Figure 11 is a sectional elevation of the valve controlling the returnof condensed vapor to the evaporator;

Figure 12 is a sectional elevation of the valve controlling the flow ofvapor from one of the evaporators;

Figure 13 is a partial diagrammatic view illustrating the modified meansof controlling activation;

Figure 14 is an elevation, partly in section, showing the constructionof an adsorber unit;

Figure 15 is a plan view of the tubular evaporator;

Figure 16 is an elevation showing an ar-.

rangement in which the valve controlling flow from the tubularevaporator isomitted; and

Figure 17 is a diagrammatic elevation of a modification.

Referring to Fig. 1 of the drawings, the form of apparatus there showncomprises an evaporator E adapted to contain an evaporable liquid suchas brine, anadsorber A in communication therewith and charged with asolid, porous adsorbing material suchas silica gel, and a condenser Cadapted to condense the vapor liberated from the adsorbing material andreturn it to the evaporator.

The evaporator may be of any suitable construction to present as large asurface as possible. In the form shown, it comprises a series ofhorizontal superposed manifolds 20, 21, 22 and 23. As shown in Fig. 15,each of these manifolds comprises a header 24 and a series of tubes orpipes, each of which is closed at one end and at the other end welded tothe header. Each header has at one end an upwardly inclined portion 26connected to a riser 27. The vapor evaporated from the liquid in themanifolds flows through the inclined portions 26 tothe riser 27. Asexplained hereinafter, liquid is supplied to the upper manifold andoverflows through a tube 28 into the second manifold. Likewise, each ofthe manifolds is provided with an overflow tube 28 for supplying thenext lower manifold. The upper ends of the tubes 28 project into theheaders 24 so that liquid cannot overflow until it has accumulated .tosuch an extent as to reach the level determined by the upper endsof thetubes 28,

It will be noted thatthis evaporator presents a large external surfaceso that it is responsive to changes of temperature in the ing ice, thenan additional evaporator 29 may be provided. As shown, this may be inthe form of a tank having depressions 30 in its upper side to receivecans or forms containing the water to be frozen. Vapor from the liquidin the tank 29 passes out through the pipes 31 and 32 leading to a riser33. The tank 29 may be supplied with liquid from 'the lower manifoldthrough an overflow pipe 34 similar to the overflow pipes 28.

The vapor from the evaporator is conducted to the adsorber. For thispurpose the risers 27 and 33 communicate with a conduit 35 leading tothe adsorber. In order to make ice in the ice-making evaporator, thetemperature of the brine therein should be 10- to 18 F., which is lowerthan the temperature of the brine in the upper evaporator. To obtainthis result, at the beginning of an adsorption cycle communicationbetween the upper evaporator and the adsorber is cutoff until thetemperature of the brine in the lower evaporator has been reduced tosome predetermined temperature (say 10 to 189 F Then the riser 27 isplaced in communication with the adsorber and remains so until the endof the adsorption cycle. This may be accomplished by a valve 36controlled by a thermostat having a temperature responsive element 37.As shown, this elementis disposed in the icemaking tank.

One form of the valve 36 is shown in detail in Fig. 12. It comprises abody 38 having an inlet 39 to which the riser 27 is connected, and anoutlet 40 to which the conduit 35 is connected. Within the body is avalve seat 41 with which the valve member 42 co-operates rThe valve 42is moved to and from the seat 41 to control the flow of vapor from theevaporator. For this purpose the valve 42 is carried by the end memberor diaphragm ofa bellows-tube 43 of metal or other suitable materialwhich, at the end opposite the valve, is secured to the valve body. Asshown, thisis accomplished by securing the end of the bellows to aflange 44 on a tube 45 which projects through the removabl end wall 46of thevalve body. This tube has a small bore and the end of the tube 47extending to the temperature re-, sponsive element 37 is securedthereinas-by sweating or welding. The joint between the flange 44 andend wall 46 must be absolutely gas-tight and so the tube 45 is welded asat 48 to the end wall. To relieve strain on this turn is forced againstthe end wall 46. Thus by screwing up the nut 49,-the end wall 46 isclamped between the flange 44 and the sleeve 50.

The thermostat, comprising element 37,

tube 47, and bellows-tube 43, is filled with a suitable liquid that willexpand the bellows when the temperature rises. Thus, when thetemperature of the brine in the ice-making evaporator 29 is above thepredetermined value, the valve 43 is held against its seat and no vaporis evaporated from the upper evaporator. The ice-making evaporator, onthe other hand, is in direct communication with the conduit 35 by meansof the riser 33, so that vapor is evaporated fromthe same, whereby thetemperature of the brine therein is rapidly reduced. When thistemperature has been lowered to the predetermined value, the valve 42opens, thereby placing the upper evaporator in communication with theconduit 35. This valveremains open during the balance of the adsorptioncycle.-

The conduit 35 leads to a valve housing 51, which in turn communicateswith the header 52 of the adsorber. In the form of adsorber here show-n,the header 52-has a plurality of pipes 53 welded thereto, the lower endsof thepipes bein closed. A tubular screen 54 (Fig. 14) is Tastened ineach pipe, extending throughout the length thereof, and projecting intothe header. The annular spaces between the screens and inner surfaces ofthe pipes are filled with silica gel or other suitable adsorbent. Ofcourse, as many of these adsorber units or manifolds will be used as arenecessary to give the required refrigeration. For the smaller units, onesection is sufiicient. This adsorber manifold is surrounded by a heatinsulating casing 55, the upper end 56 being funnel-shaped and providedwith a damper 57 which controls communication with the atmosphere.

Any suitable means may be used for activating the adsorbing material. Inthe form 1 of apparatus illustrated, a gas burner 58is "heating mediumaround and along the entire length of the tubes, when the adsorbingmaterial is being activated, and also induces a a current of air upwardswithin the casing so as to cool the adsorbing material after activationand during the adsorption cycle.

A valve 60 within the casing. 51 controls the valve open.

evaporator. Normally this valve is open, but when the adsorbingmaterialv is bein activated, this valve is automatically close For thispurpose the'lower end of the stem 61 of the valve rests onabello'ws-tube 62- of the type already described. The interior ofthisbellows is in communication, through tube 63, with'a temperatureresponsive element .64, disposed adjacentthe tubes of the ad sorber.Normally-the temperature of the ad sorber is relatively low and thebellows 62 is therefore contracted, the spring65 holding As soon as theheating means is turned on to activate the adsorbing material, theelement 64 is afie'cted, expanding the bellows 62 and closing the valve60, thereby cutting off communication between the evaporator and theadsorber! This valve will remain closed until the temperature in theadsorber drops sufficiently to permit 'contraction of the bellows 62,when it opens being aided by spring 65.

During activation of. the adsorbing material, the vapor liberated isdischarged into the valve casing 61 which, below the valve 60, hascommunication with a condenser. .As shown, the vapor flows from thevalve casing 51 through a short tube 66 into a chamber 67' in a housing68. This housing is divided into two chambers by a horizontal partition69. r The lower chamber is partially filled with aliq'uid, like mercury,and a tube projects from the partition 69 downwardly so that its lowerend is submerged in the mercury. Above the surface of the mercury andbelow the partition 69', this chamber has communication, by means of atube 71, with another small housing 72.

When the vapor liberated from the adsorber has its pressure slightlyincreased, it flows from the chamber 67 downwardly through the tube 70and bubbles up through the mercury, then flows through tube 71 intothehousing 72. The housing 68 with the partition 69, tube 70 and themercury thus constitutes a seal or check valve to prevent vapor passingdirectly to the condenser when the adsorber is adsorbing. The chamber 67is of suflicient size to hold all the mercury,

so that if anything should occur to force the mercury through tube 70into said chamber, it would not pass over into any other parts of theapparatus. The housing 72 contains a temperature responsive element 73for a purpose presently to be described.

The condenser connected with the housing 72 is preferably in two partsso that part of the vapor is condensed under sub-atmospheric pressureand the balance at' atmosphericpressure. It will be understood that leakinto the system, the rapidity with which the adsorbing material willadsorb the vapors is retarded. Even the slightest amount of permanentgases -will materially afi'ect the rate of adsorption.

The first stage of the condenser is shown at 74 and has one endconnected to the housing 72 and the other end to a small condensate tank75. This stage of the condenser is under vacuum. I

The second stage of the condenser is shown at 76. The vapor condensedcollects in a tank or receptacle 77 having a vent 78 open to theatmosphere. The stage 7 6 of the condenser is therefore at atmosphericpressure.

The two stages of the condenser are connected so,that when the pressureof the vapdg being condensed in the first stage builds up to such anextent as to slightly exceed atmospheric pressure, it discharges intothe second stage. For this purpose a check valve may be used to connectthe two stages.- As shown,

' a mercury check valve is employed. It'commercury 7 9 prises a closedcasing or tank 79 containing This tank is connected to the tank 75through a vertical length of pipe or tube 80. The tube is of such lengththat the difierence of levels between the mercury in the'tank 79 andthat in the tank 7 is about inches. The second stage condenser 76communicates with the tank 79 throughthe tube 81." The lower end of thetube 80 is submerged in the mercury 7 9 The tank 79 is a little largerthan necessary to contain all of the mercury, so that only a slightincrease above atmospheric pressureisrequired to force fluid from thefirst stage to the second. The pressure in the second stage of thecondenser being substantially atmospheric, a column of mercury of about32 inches in height is maintained in the tube or pipe 80. When, duringactivation, the pressure in the first stage of the condenser builds up,"this mercur is forced down the pipe 80 into the receptac e or tank 79and finally when the pressure in the first stage exceeds that in thesecond, vapor and condensate will be discharged from the lower end ofthe tube '80 and bubble up through the mercury 7 9 and then flow throughthe pipe 81 into the second stage 7 6 of the condenser; The first stageof the condenser is designed to have a capacity to condense only a partof the vapor liberated, so that gradually the pressure of the vapor inthis first stage will increase until it becomes sufficient to causedischarge into the second stage. i

If all the liberated vapor were condensed at atmospheric pressure, itwould be necessary to heat theentire mass of adsorbent to thetemperature corresponding to this pressure before any .vapor would bedischarged into the condenser. With the two stage method, vaporbegins tobe liberated and condensed, almost immediately follow'ng the ignition ofthe burner. By the time the premure in the.

first stage has increased to atmospheric, a conis returned to theevaporator through this .tube 82. A cooiing device 82 may be pro-"vided, if desired. The flow of the condensed Vapor back into theevaporator is controlled .sy a valve 83. One form of valve suitable forthis purpose is shown in Fig. 11. It comprises a body 84 having an inletto which the pipe 82 is connected and anoutlet 85 leading to theevaporator. The flow from the inlet to the outlet is controlled by'avalve 86 cooperating with a valve seat 87. This valve 86 is carried onthe end wall of a bellows-tube 88 of the same construction as describedin connection' with valve 36, and secured to the valve body in the sameway. A temperature responsive element 89 inthe evaporator isconnected'by a tube 90 with the bellows 88. When the temperature ofthebrine in the evaporator rises, the bellows 88 is expanded, therebyopening valve 86 and permitting re turn ofcondensed vapor to theevaporator. "The evaporator being under vacuum and the tank 77 atatmospheric pressure, there is no diflieulty in effecting this return.

The starting and stopping of the activation of the adsorbing material iseffected automatically. As shown, a gas or fuel supply pipe 91 isconnected to a valve 92, the outlet of which is connected by means ofpipe 93 .to the burner 58 under the adsorber unit. This valve isnormally closed, but means is provided so that it is opened whentheamount of condensate in the tank 77 is sufiiciently reduced. As thedischarge of condensate from the tank 77 to the evaporator is controlledby valve 83 in turn responsive to the temperature of the brine, it willbe seen that the fuel valve 92 is thus indirectly controlled by thetemperature of the brine.

One form of valve 92 and the device for controlling the same is shown indetail in Figs. 6, 7 and 8. The valve proper comprises a valve body 94divided into two compart-' ments 95 and 96 by means of a partition 97.The inlet pipe 91 communicates with the compartment 96 and the outletpipe 93 with the compartment 95. The partition 97 has an opening 98thereto, and this opening, in the form shown, is controlled by a ballvalve, 99. Normally this valve is seated in the opening, thereby closingthe same. Means is profuel to the burner under theadsorber w videdto-move it from its seat and thus supply I the amount of condensate inthe tank 77 falls sufliciently. For this purpose, there is a float 100in the tank which carries a stem 101 that Ill flange 106, and thisflange supportsthe valve:

92. Thestem 101 at this point isv guided for vertical movement by asleeve 107 carried by a flange 108 clamped between the flange and aflange 109. on the lower end of an upwardly extending tubular housing110. The vent 78, previously mentioned, is provided in this flange 108.portion of the housing 110 is cut away as shown at 111 for the meansconnecting the valve and the float stem, which means actuates the valve.As shown, the stem 101 has a collar 112 set-screwed thereto, and thiscollar carries an adjustable screw 113 the projecting end of which isadapted to contact with a lever 114 rigidly secured to a short shaft 115extending into the compart-' ment96 of the valve body. Within the valvebody the shaft 115 has secured thereto a depending arm 116 which in turnnear its free end engages the lever 117 near its pivot. The lever 117 inturn near its free end engages a bent lever 118 pivoted at 119. The freeend of this bent lever 118engages the ball valve 99. Thus when the lever114 iszdepressed, the amount of movement transmitted to valve 99 isgreatly magnified. In other words, a very slight movement of lever 114will. push valve 99mm its seat. The lever ll4is made in two partspivoted together at 120 and held against breaking by spring 121'.

This-construction is provided so that if the motion of the float is sogreat as to force lever 118 against the partition 97, the lever 114 can'yield. The valve actuating parts are held in the position shown in Fig.6 by. the spiral spring 122 on the shaft 115.

This structure provides a means for opening the valve suddenly insteadof gradually. Means is also provided to hold the valve in this openposition until substantially all of the vapor has been liberatedfrom-the adsorbing material. It will be seen that liquid will graduallyaccumulate in the tank 77, while the adsorbing material is beingactivated, and this would cause the float to rise and close the valvebefore all of the vapor had been liberated from the adsorbing material.To prevent this, the housing 110 above the upper end of the float stem101 supports a bellows-tube 123 of the type already described. Thisbellows is in communication with the temperature responsive element 73through the tube124, these parts, like the other thermostats alreadydescribed, being \filled with a suitable liquid so that changes intemperature in the temperature responsive element will cause expansionsand contractions of the bellows 123. The lower end of the bellowscarries a member 125 provided with a socket into which the upper end offloat stem 101 projects. After the fuel valve has been turned on, andactivation of the material started, the vapor liberated will come incontact with-temperature responsive element 73. This vapor being hotwill expand the liquid in the element, thereby expanding bellows 123 andforcing member 125 down against the upper end of the float stem 101.Thus the float stem will be held in position to keep the fuel valveopenuntil such time as the temperature of the vapor around thetemperature responsive element 73-falls. This will not occur untilsubstantially all of the vapor has been liberated from the adsorbingmaterial. During this period of activation,of

cours'e liquid has been accumulating in the tank 77 tending to raisefloat 100 and thereby close valve 99. So, when the temperatureresponsive element- 71 permits contraction of the bellows 123, the floatwill rise, permitting cut off further supply of,

valve 99 to seat and fuel.

During this activation, the vapor liberated fills the adsorber,condenser and associated parts, thereby driving ahead of it any air orpermanent gases, in the same manner that air is driven out of asteam-heating-radiator when the steam is turned on. Any air or permanentgases that have leaked into the system or accumulated in any way arethus vented through the opening 78 from the tank 77 As .the liquid inthis tank is at an elevated tem-- perature, practically no air will beentrained therewith when it is discharged from the tank and returned tothe evaporator.

After the apparatus has been built, to produce the vacuum therein andrender the plant ready for operation, any suitable method may beemployed. If desired, a vacuum pump may be connected to any suitablepart of the apparatus to exhaust the air. Preferably, however, theadsorber is heated, thereby driving ofl vapor from the adsorbingmaterial -and expelling air through the vent opening 78. Perhaps all ofthe air or permanent gases will not be eliminated from the system thefirst time, but enough will be discharged so that the refrigeratingcycle will continue automatically. After one or two activations, allofthe permanent gases will have been eliminated from the system, andthereafter the small amounts thatmay leak in or accumulate will beexpelled during each activation. The operation briefly summarized asfollows:

Vapor is eva orated fromthe evaporator and conducted y a pipe 35 to. theadsorber. Where the evaporator is provided with an of the apparatus maybe ice-making part, the first part of this vapor comes from saidice-making compartment,

the valve 36 cutting-ofi the flow of vapor from the upper portion oftheevaporator. After the brine in the ice-making compartment has itstemperature sufliciently lowered, the valve 36 opens so that thereafterduring the adsorption cycle, vapor is also taken from the upperevaporator.

During this time, condensed liquid in the tank 77 is being returned tothe evaporator through the pipe 82, the valve 83 controlling the flow inaccordance with the refrigerating effect, that is to say, the lower thetemperature of the brine, the smaller the return flowof this liquid.Finally, when enough liquid has been discharged from tank 77, the float96 falls sufliciently so that gas valve 92 is opened. Gas is thussupplied to the gas burner 58 under the adsorber unit and is ignited bythe pilot light 126. Now the adsorber is heated and vapor is liberatedfrom the adsorbing material and discharged into the condenser. The firstportion of the vapor liberated from the adsorbing material is condensedunder vacuum in the first stage 74 of the con-.

denser. Finally, the pressure in this first stage of the condenserbuilds up sufliciently so that it discharges into the second stage oratmospheric condensing stage of the condenser. Then the balance of thevapor is condensed at atmosphericpressure. All of the condensatecollects in the tank 7 7. The hot vapor coming over from the adsorberstrikes the thermostat element 7 3, thereby expanding bellows 123 intocontact with the stem 101 of the float 100, thus holding the gas valve99 open until substantially all of the vapor is driven oil from theadsorbing material.

Then the temperature of this vapor falls so that the bellows 123contracts and valve 99 may close if sufiicient liquid has accumulated inthe tank 77. After the supply of heating medium has been turned off inthis manner,

' cool air enters at the bottom of the adsorber casing and flowsupwardly around the tubes. thereby cooling the same. After a time thepressure in the adsorber falls sufiiciently so that the valve opens andanother absorbing cycle is started.

As stated, preferably a brine is used as the refrigerant, but otherliquids that can be evaporated under the conditions might be used. It isalso preferred to use highly porous granular silica gel in the adsorber,but other adsorbent gels or materials might be used if they havesufiicient adsorbent capacity. As

a measure of the adsorptive capacity of an ad-.

sorbent suitable for this invention, it may be said that it shouldhaveenough small pores so that it will adsorb at least 10% of its ownweight of water when in equilibrium with water vapor at a temperature of30 C. and

' a partial pressure of 22 mm. of mercury.

Although the invention has been described as employing gas for theheating medium, it is obvious that electricity, kerosene or othersuitable heating mediums might be ,em, ployed. Of course, if electricitywere used, the valve 92 would be replaced by an electrical valve, thatis to say, -a switch.

Another method of controlling the fuel valve 92 is illustrated in Fig.13." Inthis modification, the valve is controlled directly by thetemperature of the brine in the eyaporator, instead of indirectly fromthis source through the float. The vapor condensed in the condensercollects in the tank -77 and is returned to the evaporator through thepipe 82 in the same manner as already described. For controlling the gasvalve, there is provided a temperature responsive element 140 in thebrine in the evaporator. This element is connected by means of a tube141 with a bellows-tube 142. These elements are filled with a suitableliquid and constitute a thermostat. The lower end of the bellows-tube142 is disposed to contact with the valve lever 114 of the sameconstruction as described in connection with the first form of theinvention. Whenthe temperature ofthe brine rises, the bellows 142expands, thereby depressing the lever 114 and opening the gas valve. Thelever is held depressed, and thus the valve open until substantially allof the vapor has been liberated from the absorbing material, by means ofa second thermostat, consisting of the temperature responsive element73, already described, and a tube 143 connecting this element to a'oellowstube 144, adapted to contact with the lever 114. The hot vaporbeing liberated from the adsorbing material expands the liquid in thethermostat, by coming in contact with the temperature responsive element7 3. The expansion of this liquid causes the bellows 144 to expand andhold the lever 114 depressed until such time as substantially all of thevapors have been liberated from the adsorbing, material.

In Fig. 16 is illustrated a form oftheapparatus in which the valve 36,previously described,- is eliminated. In this construction, the upperevaporator E is charged with a weaker brine than the ice-"makingevaporator 29. Thebrine in the latter is of such concentration that itwill freeze at about 10 to 15 F. When the apparatus starts on anadsorbing cycle, vapor is evaporated. from both containers 30. Finally,the brine in this icemaking tank also freezes so that evaporaof loweringthe temperature of the brine in the ice-making tank sufficiently tofreeze the'water in the containers, and this can be effected without thevalve 36.

For the larger installations, it is desirable to have a plurality ofadsorber units or manitical' spindle 165, aligned with the valvespinfolds. By providing several of these units,

each of a relatively small capacity, and activating the same frequently,the adsorbing material is utilizedto av maximum degree. Furthermore, thetotal weight of adsorbent for aplant of given capacity may be a.minimum.

An apparatus of this type is diagrammatically illustrated in Figs. 2, 3,4, 5, 9 and 10 R,eferring to Fig. 2, the evaporator may beof the sameconstruction as already described, and may or may not have the icemakingcompartment, as desired. It is connected with the adsorber assembly bymeans of aconduit 150, which ends in a header. 151. In the formillustrated, there arethree adsorber units, A A and A each consisting ofan adsorber manifold like that already described, and each disposedwithin a heat insulated casing. Each casing has a. burner 152, 153 and154 near the bottom thereof and a damper at the top to control thecirculation of the heating medium and the cool air.

The vapor from theeva-porator. is thus conducted to the header 151. andpasses through the vapor valves 155, 156 and 157 to the adsorbersections A, A and A respectively. These individual valves 155,156 and157 provide means so that the adsorber sections can be cut off from theevaporator when being activated. A vertical section through these,valves is, shown in Fig. 4. The parts are shown with valves 156 and 157open and valve 155 closed, as the adsorber section A is being activated.Each of these valves may comprise an upper bellows-tube 158, a lowerbellows-tube 159 and a spindle 160, connecting the two which carry thevalve member 161 adapted to seat against the partition .162 and closethe opening .therethrough. The lower bellows-tube 159, as illustrated inFig. 3, is connected by means of a tube 163 to a temperature responsiveelement 163, disposed adjacent the tubes of the adsorber.- It will beunderstood that there is one of these temerature responsive elements foreach of the ellows-tubes 159 so that the bellows 159 will be responsiveto the temperature of its particular adsorber section. The diaphragm 164of the upper bellows-tube 158 carries a verl dle 160. This spindle 165projects above the top of the valve proper, for a purpose presently tobe described.

When the vapor valve is closed and the adsorber section is beingactivated, vapor liberated from the adsorbing material will pass intothe valve casing, then through conduit 166 (Fig. 3) into a chamber 67 ofa casing 68 of the same construction as described in connectionwith thefirst form of the apparatus. It will be understood that there is one ofthese casings 68 for each of the vapor valves. The vapor then passesfrom chamber 67 downwardly through the tube 70, bubbles up throu h themercury in which the lower end of this tube is submerged, and thenpasses through a short tube 167 into a header v169. This headerdischarges into the condenser which may be of the same construction asalready described. Near the discharge end of this header 169 is atemperature responsive element 170, connected by a tube 171 to abellows-tube 123,,the same as described in connection-with the firstform 'of the apparatus, this bellows-tube acting to hold the fuel valveopen as long as any vapor is being discharged from the adsorber sectionbeing activated.

Means is provided so that each ofthe adsorber sections will be activatedin rotation,

and at intervals depending upon the temperature of the brine in theevaporator or the amount of vapor condensed. For accomplishing theseends, the gas valve 92 is connected by means of a pipe 172 to adistributor D. This distributor, as shown in Fig. 9,

has a chamber 173 into which the pipe 172 discharges, and which, throughindividual valves 174, may be placed in communication with pipes 175,176 and 177 leading respectively to the burners 154, 15.8 and'152. Thevalves 174 are opened in rotation and sue cessively by means of a cam178 on a plate 179 non-rotatively mounted on a shaft 180. There isprovided for each of the stems of the valve 174, a rocker 181 whichengages the end of the stem and carries a roller 182 adapted to be acted'on by the cam 178. Thus, as the shaft 180 is rotated, cam 178 willsuccessively engage rollers 182 and thus open the valves 174 inrotation.

The movements of the vapor valves 155, 156 and 157 are utilized torotate the disc 179 at the proper times. For this purpose, the shaft 180at one end has a gear 183 (Fig. 5) which meshes with a gear 184 mountedto rotate with a ratchet wheel 185. A shaft 186 is- The upper end ofeach of the valve stems 165 is adapted to engage one of the arms 187,188 and 189. In the position of the parts shown in Fig. 4, the left-handvalve stem 165 has engaged the arm 187, thereby rotating the shaft 186and turning the pawl arm 190 in a counter-clockwise direction, as viewedin Fig. 10. This valve stem is associated with the valve 155 andadsorber section A which is being activated at this time. After theactivation has been completed, the valve member 161 of the valve 155will open, there by lowering valve stem 165 and permitting shaft 186 toturn in .a clockwise direction, as

viewed in Fig. 10. The spring 192 will effect this rotation and it willbe communicated, by means of pawl 191 to theratchet wheel-185, which,through the gearing, will rotate the disc 179 and bring cam 178 underthe next roller, thereby opening the next valve 174, so that the nexttime the main gas valve -92 is opened,.the adsorber section A will beactivated. This will occur when the float falls sufiiciently to open themain gas valve 92. Then the burner 153 of the adsorber A will be ignitedand temperature responsive element 163will thereby be heated, causingthe valve 156 to close. This closing movement will raise stem 165thereby through arm 188, rotating arm186 in. 'a counter-clockwisedirection, as viewed in Fig. 10, so that when this valve 156 latercloses, rotationof the shaft in the return direction will permitrotation of the cam disc 179, thereby opening the next gas distributorvalve 174 and placing the parts in position so that the next timethemain gas valve 92 opens, the adsorber section A will be activated. Itwill be seen, therefore, that the adsorber sections are activated insuccession andat intervals, depending upon the temperature of the brinein the eva orator.

ig. 17 shows a modified arrangement of the parts between the condenserand the evaporator, it being understood that the parts shown in thisfigure are adapted for use with the singleunit adsorber shown in Fig.1or with the plurality of adsorber units shown in Fig. 2.

, The arrangement shown in Fig. 17 is designed to accomplish twopurposes as follows:

1. To regulate the adsorption period for the upper evaporator and thelower, or icemaking, evaporator.

2. T o prevent air entering the evaporator from the float chamber incase the water leaks out of the latter.

The evaporator E may be of any suitable construction and is designed forrefrigerating the chamber and the evaporator E for making ice'aspreviously described. Consequently the brine in the evaporator E must bekept at a lower temperature than that in the evaporator E.

columndecreases.

The vapor evaporated from the evaporator E passes through pipe 200 tothe casing 201. Projecting from the bottom wall of this casing is anannularpartition 202. A .conduit 203 leading to the'adsorber projectsthrough the said bottom wall and -'into the space enclosed by theannular artition 202. The ice making evaporator is in communication withthe conduit 203 by means of a pipe 204. A cap 205 is disposed over theupper end of the conduit 203. The vertical wall of this cap is luted inmercury 206 in the annular space between the conduit 203 and thepartition 202. As described hereinafter, the level of the mercury 206rises and falls in accordance with the amount of water above the floatin the associated part of the apparatus. The cap 205 is kept out ofcontact with the upper end of the conduit 203 by being carried on thefloat 207 disposed in the mercury 208 in the annular-space between thepartition 202 and the outer wall of the casing 201.

This mercury 208 is the upper portion of the barometric column 209,so'that the level X of mercury rises and falls with changes in theatmospheric pressure. The annular space just inside of partition 202 isin communication with a chamber 210 by means of the tube 211. Thischamber in turn is connected by means of tube 212 to a float chamber213. The vapors-condensed in the condenser C flow into the casing 214which at 215 has a vent to the atmosphere and which is connected by tube216 with the float chamber 213. The mercury in the space within thepartition 202, the tube 211 and chamber 210 is balanced by the watercolumn in tube 212, float chamber 213 and tube 216 and the at--mospheric pressure on the top of the water in the casing 214.Consequently the level of the mercury 206 varies with atmosphericpressure and the height of the column of water just mentioned. Inasmuchas the level X of mercury depends on the atmospheric pressure, and thelevel of mercury 206 de- 206 will fall until it is below the lower edgeof the cap 205. This will place the evaporator-E in communication withthe conduit 203, and this communication will not be interrupted untilthe height of the water column is increased the necessary amount.

From the foregoing it is apparent that the ice-making evaporator E isalways in communication with the conduit'203, whereas evaporator E is.not in communication with said conduit until the height of the water So'when beginning an adsorbing cycle, vapor is first taken from theice-making evaporator E, thereby rapidly lowering its temperature to thedesired point. During this time the waiter level'in casing 214 andconduit 216 has fallen so that, at the desired point communication isestablished between evaporator E and conduit 203, because of the mercurylevel 206 falling below the cap 205. Thereafter vapor will be taken fromthe evaporator E as well as from the ice-making evaporator E.

The water condensed in the'condenser C flows into the casing 214,conduit 216, casing 213, tube 212 and chamber,210.- The float 217controls the gas valve 92 in the manner described in connection with theother forms of the invention. The atmospheric pressure on the condensedwater forces it from chamber 210 up tube 218 to the valve 83 describedin the other forms of the invention, which controls the rate of thereturn ofthe water to the evaporator E.

. In the operation of these parts, at the close of a period ofactivation, the water level in casing 214 is relatively high because thevapor driven oif from the adsorbing material during activation has beencondensed and collecte'd. Consequently, the cap 205 is luted in themercury 206, and when the adsorbing period begins, communication betweenevaporator E and the adsorber is thereby cut off, but thereiscomm'unication between the adsorberand the ice-making evaporator E.The brine in E therefore, is rapidly cooled to the desired temperature.The water level in casing 214 and tube 216 gradually falls because thewater is being continually returned to the evaporator E. When ,thewaterlevel has fallen to a desired point, say 219, the mercury level 206 hasfallen a suflicient amount so as to be just below the bottom edge of thecap 205. Evaporator E is thereby placed in communication with theadsorber-conduit 203 and the brine in evaporator'E is then chilled tothe desired temperature. The water level 219 continues to fall andfinally reaches the level, say 220, when the float 217 begins to fall,and thereby opens gas valve 92 and starts an activating period. Thestarting of this activation. as described in connection with the otherforms of the invention, causes the mainvapor valve adjacent the adsorberto close so that communication between the adsorber and the evaporatorsis cut off. Very shortly after this activating period has been started,condensed water will' flow into casperiod, vapor is always taken fromthe icemaking evaporator, but-from the refrigerating evaporator, only aportion, of the time.

In this manner the brine in the ice-making compartment is kept at alower temperature than the brine in the refrigerating evaporator. I

This device also acts to prevent air entering the evaporator E if thewater column falls to such an extent as to open the lower end of tube218. As previously pointed out, the level of mercury 206 is maintainedby the water column and atmospheric pressure on the top of the watercolumn. Consequentl when the water column decreases in heig t the levelof the mercury 206 falls and the mercury 206 in casing 210 therebyrises. The parts are proportioned sothat when the water column falls tothelevel 22-1. the mercury 206 will have risen to a'height above thelower end of tube 218, thereby sealin the same. This will prevent theforcing'o any more water or air throughthe tube 218 into evaporator E.Of course, if the water level falls to 22l or .thereabouts and themercury level 219 in the casing 210 rises to a point above the lower endof tube 218, the'mercury will enter this tube and rise therein. Duringthe next activating period the water level 221,

of course, will rise, thereby depressing the mercury in chamber 210untifthe lower end of tube 218 is opened. At the moment this tube isopened, it may be that the first rush of water upthrough the same wouldtend to carry some mercury over to the valve 83. To prevent this,theexpansion chamber 222 is provided. This takes care of any mercurythat might be carried over to said valve, and after the first rush ofwater, the mercury will fall back into the casing 210.

It will be noted that the valve 104111- the forms of the invention shownin Fi 1 and 2 has been omitted. This form of t e'apparatus, will act,satisfactorily without the valve 104, but if desired the valve may beprovided, and in this case the device will act to secure the sameobjects.

In the normal operation of the apparatus, the water level willnotordinarily fallto any such level as indicated at 221. However, if therefrigerating apparatus is shutdown by turning off the supply of gas,the water will gradually be returned to the evaporator so that the levelwill fall to the point indicated at 221. If the present device were notprovided, air would then pass over to the evaporator and the apparatuswould become all bound. With the device described herein, this conditioncannot occur, and .even if the apparatus has been out of operation for along period, it can be again set in operatlon 1 without anydifliculties.

Where the float is provided with a valve like 104, this valve willprevent the water from falling to the level 221 unless the valve leaks.So where such val e 104 is provlded, the device justdescribed willprevent air passv 7 gkgver to the evaporator in case such valve e v I 1Where the device shownin Fi 17 is assoevaporator is one or more alwaysin communication wi adsorbers, so that there is continualevapora tionfrom this evaporator. The evaporator E for refrigerating the chamber,however, is periodically connected with the adsorbers so thatevaporation from this evaporator is not continuous.

If desired, the valve 83 and the associated thermostat of all forms ofthe invention may be replaced by a manually controlled valve.

Preferably silica. gel is employed as the porous adsorbing material. Inorder to give a rule for determining an adsorbent suitable for thepresent invention, it may be stated that the material should have poresof such size that it will adsorb water vapor to such an extent as tocontain not less than 10% of its own weight of water when in equilibriumwith water vapor at C. and a partial pressure of substantially 22 mm. ofmercury. A good silica gel under these conditions should adsorb from 21%to of its own weight of water. If desired, other gels, such as the gels,of tungstic oxide, stannic oxide,alumia num oxide and titanium oxide,might be used provided they are made so as to have the required finelyporous structure.

Having thus described the invention, what is claimed as new and desiredto be secured 35 by Letters Patent is: V

1. A method'of refrigeration consisting in evaporating a liquid,adsorbing the vapor in a porous material,in the absence of permanent'gases, activating the adsorbent to liberate the adsorbed vapor,condensing the liberated vapor, returning it to the liquid, andmaintaining the system free of permanent gases by sweeping the gases outto the atmosphere during, and by, the activation of a the adsorbent. r

2. A method of refrigeration consisting in evaporating a liquid,adsorbing the vapor in a solid porous adsorbent in the absence ofpermanent gases, activating said adsorbent to drive off the adsorbedvapor and free the system .of any permanent'gases, condensing the vapordriven off from the adsorbent, separating the condensate and anypermanent gases and returning the condensate to be evaporated again. r

3. A method of refrigeration consisting in evaporating a liquid,adsorbing the vapor in a solid porous material in the absence ofpermanent gases, activating the adsorbent to liberate the adsorbedvapor. condensing the liberated vapor and returning the condensate. tothe liquid, a portion of said liberated vapor being condensed undervacuum and the remaining portion atv atmospheric pressure. I

4. The method according to claim 3 with the further step of separatingany permanent I gases from the condensed vapor. ciated with a pluralityof adsor rs such as 5 shown in Fig. 2, the ice-m 5. A method ofrefrigeration consisting evaporating a liquid, adsorbing the vapor in asolid porous material in the absence of perand returning it to theliquid, and controlling the activation jointly by the amount of con- 7densa'te collected and the temperature of the liberated vapor.

6. A method of refrigeration consisting in evaporating a liquid,adsorbingthe vapor in a solid porous material in the absence of per--manent gases, activating the material, a portion of the adsorbed vaporbeing liberated at sub-atmospheric pressure and the balance atatmosphericpressure, and using the ma-' terial to adsorb more of thevapor evaporated from the liquid.

7. Refrigerating apparatus of the character described including incombination, an evaporator, anadsorber communication with saidevaporator and charged with a solid porous adsorbing material, means toactivate said material, two condensers in series between said adsorberand evaporator, one adapted to condense under vacuum and the other atatmospheric pressure and means to return the condensate to theevaporator.

-8. Refrigerating apparatus according to claim 7 in which there is avent to the atmosphere from the atmospheric condenser to permit theescape of permanent gases.

9. Refrigerating apparatus of the character described including incombination, an

evaporator, an adsorber in communication with said evaporator andcharged with a solid porous adsorbing material, means to activate-adsorbing material, means to activate said material, means to condenseat sub-atmospheric pressure a portion of the vapors liberated from thematerial during activation and to condense the balance at a higherpressure, and mean's to return the condensate to the evaporator.

12. Refrigerating apparatus of the character described including incombination, an evaporator, an adsorber charged with a solid porousvapor-adsorbing material, means controlling communication between saidevaporatorand adsorber, means to activate said adsorber when saidcommunication is .cut

off, means to condense the vapor liberated from the material andseparate the condensate and. permanent gases, and means to return thecondensate to said evaporator.

13. Refrigerating apparatus of the character described including incombination, an

evaporator, an adsorber charged with a sohd porous vapor-adsorbingmaterial, means controlling communication between said evaporator andadsorber, means to activate said adsorber when said communication is cut011:, a condenser connected to said adsorber to condense the vaporsliberated from the material during activation, means to permit escape ofpermanent gases from the condensed vapors, and means, to cool thecondensed vapor and return it to the evaporator.

- 14. Refri eratin apparatus of the character descri ed inc uding incombination an evaporator, an adsorber. in communication therewithcharged with a solid porous adsorbing material, means to activate thematerial, twocondensers in series between the adsorber and evaporatorone being in communication with the adsorber and adapted .to condense aportion of the liberated vapor at sub-atmospheric pressure and the otheradapted to condense at a higher pressure, means.

connecting the two condensers constructed and arranged to permit thedischarge from the first condenser to the second condenser when thepressure in the first slightly exceeds that in the second, and means toreturn the condensate to theevaporator.

15. Apparatus accordlng to claim 14 where in the means connecting thetwo condensers is a check .valve.

16. Apparatus according to claim 14 where- '49 in the means connectingthe two condensers return.

V 18. Apparatus according to claim 17 wherein the valve is controlled bythe temperature of the liquidin the evaporator.

19. Apparatus of the character described including in combination, anevaporator, an

adsorber in communication'therewith and charged with a solid porousadsorbing material, means to activate said material, vapor condensingmeans having a normally open vent to the atmosphere, 9. check valvebetween said condensing means and adsorber and means toreturn the thencool saidv material evaporator. a v

20. Apparatus of the character described including in combination, twoevaporators, an adsorber in communication therewith charged with a solidporous adsorbing macondensed vapor to the' terial and means controllingthe flow of vapor from one evaporator to the adsorber in ac- -cordancewith the temperature of the liquid in the other evaporator.

21. Apparatus of the character described including in combination anevaporator, an adsorber in communication therewith and charged with asolid'porous adsorbing material, a. normally open valve between saidevaporator and adsorber, means to activate the adsorbing material andheat actuated means to close said valve automatically during saidactivation.

22. Apparatus of the character'described including in combination anevaporator, an

adsorber charged with solid porous adsorbing material, a conduitconnecting said evaporator and adsorber, a'normally open valve in saidconduit, means to activate and rior to adsorbing, and means to closesaid va ve during said activation and cooling prior to adsorbing.

' 23. Apparatus'of the character described including in combination anevaporator, an

adsorber charged with solid porousadsorbing material, a conduit:connecting said evaporator and adsorber, a normally open valve in saidconduit, ineans to activate said material, and means actuated by theactivating means to close said valve during activation.

24. Apparatus of the character described including in combination, anevaporator, an adsorber charged with a solid porous adsorb- .ingmaterial, a conduit connecting said evaporator and adsorber, a normallyopen valve in said conduit, means to heatthe material to activate it,and means to close said valve when the temperature of the materialincreases.

25. Apparatus of the character described, including in combination anevaporator, an adsorber char ed with a solid porous adsorbing material,a conduit connecting said evaporator and adsorber, a normall. open valvein said "conduit, means to heat t e material to activate it, and meansto close said valve when the tem erature in the adsorber rises and holdssai valve closed until the temperature and-pressure an to amounts 4suitable for adsorbingi 26. Apparatus of t e character describedincluding in combination, an evaporator, an adsorber in communicationtherewith and charged with a solidporous adsorbin material, means toheat said material to 11 erate the adsorbed vapors, means to condensesaid vapors and return them tothe evaporator, and. means governedjointly by the condensate and the temperaturelof the liberated vaporsfor controllin said heating means.

27. Apparatus of t e character described including in combination, anevaporator, an

adsorber in communication therewith and charged with a solid porousadsorbing max teria means to activate said material started and stoppedby the temperature of the liquid in the evaporator, and means tocondense the vapors' liberated during activationand return them to theevaporator.

29. Apparatus ofthe character described including in combination, anevaporator, a-

therewith, each charged with a solid porous adsorbing material, saidcommunication for each adsorber in rotation and means to activate thematerial in the adsorber thus cut out, said last mentioned means beingactuated by the first mentioned means of t e previously activatedadsorber.

plurality of adsorbers in communication means to cut oil combination, anevaporator, an adsorberjn' communication therewith and charged with asolidporous adsorbing material, means to activatesaid material, means tocondense the vapors liberated during activation and having a vent to theatmosphere for freeing .the s stem of permanent gases, means to returnthe condensed vapor to the evaporator, and means to prevent air enteringsa1d vent from passin to. the evaporator.

36. efrigerating apparatus including in combination,- an evaporator, anadsorber in communicatlon therewith and charged with a solid porousadsorbing material, means to activate said material, means to condensethe vapors liberated during activation and having a vent to theatmosphere for freeing the system of permanent gases, means to return,the condensed vapor to the evaporator, and

means to prevent air entering said vent from passing to theadsorber.

In testimony whereof I hereunto aflix my signature.

ERNEST BALDWIN MILLER.

30. Apparatus according to claim 29 in i which the means to'activate theadsorbers in rotation is controlled by the temperature of the liquid inthe evaporator.

including in combination an evaporator, a plura'hty of adsorbers mcommunication therewith and each charged with a solid" porous adsorbingmaterial, means to cone dense the vapors liberated from the adsorb ingmaterial and return the same tofthe evaporator, and means to activatesaid ad:

31. Apparatus of the character sorbersin rotation "controlled by theamount of condensate.

32. Apparatus to claim which the activating means is also controlled vby-the tem rature of'the vapor liberated fromthea rbers. a 3 3.Apparatus according to claim' 29 in which theactlvating means iscontrolled by the temperature of the vapor liberated the material.

34'. ;Apparatus o f the character l includ ng in comb nation, anevaporator, 12 plurality of adsorbers each charged with a solid porousadsorbing material in communication therewith, a valve for each adsorberclose said valves in rotation, and means to activate said adsorbers,including a distributor adapted to supply the adsorbers with activatingmedium in rotation, said distributor 7 being controlled by said valves.

' 35. Refrigerating apparatus including in controlling saidcommunication, means to

